1. Field of the Invention
This invention relates to relatively compact, low cost and easy to use smoke producing apparatus including a sealed chamber within which a fluid (e.g. a heavy mineral oil) is vaporized into smoke. The smoke which exits the chamber is conducted through a fluid system for the purpose of detecting and locating leaks depending upon whether the smoke escapes from the system under test.
2. Background Art
It is known to generate smoke within a closed chamber containing an oil supply to be vaporized so that the smoke can be delivered to a fluid system in order to detect the presence and location of leaks by making visual observations whether and where the smoke escapes from the system. By way of example, U.S. Pat. No. 5,107,698 issued Apr. 28, 1992 to Leslie Gilliam discloses apparatus for testing the integrity of an internal combustion engine by producing and conducting smoke from a chamber to the intake manifold of a vacuum system in the internal combustion engine. However, the patented apparatus has a relatively complex construction and may require frequent maintenance during use.
In particular, the aforementioned smoke generating apparatus requires that the smoke generating fluid be constantly monitored by using a fill and drain port system. In addition, because a ceramic heating element is used, it is necessary to monitor and control the temperature within the chamber by using an electronic thermistor and bimetal switch control. In this same regard, the use of a ceramic heating element is an inefficient way to produce smoke and requires that the temperature of the smoke generating fluid and the resulting smoke be raised to a potentially unsafe level. Lastly, as a consequence of the openings that characterize the chamber of this prior apparatus, the possibility of spillage is increased should the chamber be tipped or accidentally fall out of an upright position.
Reference may also be made to the following United States patents which describe smoke generating apparatus:
U.S. Pat. No. 2,003,949 Jun. 4, 1935
U.S. Pat. No. 3,093,596 Jun. 11, 1963
U.S. Pat. No. 4,694,695 Sep. 22, 1987
U.S. Pat. No. 4,764,660 Aug. 16, 1998